The present invention relates to an antenna system comprising a paraboloidal mirror or reflector in which only the upper portion of the parabola is used and in which a multiple mode exciter is disposed above an approximately horizontal bottom plate. These antennas are known as Horn parabolic antennas.
For the determination of star points in radio networks it is possible to operate one operating frequency in a broadband system several times at the same location if a certain decoupling is provided between the individual beam directions. The requirement for decoupling between two beam directions operating at the same frequency, for example, in the 6GHz radio ranges, is 65 dB beginning with an aperture angle of .+-.35.degree..